site/_src/_assets/javascripts/bigchain/smoothscroll.js

//
// https://github.com/bendc/anchor-scroll/blob/master/scroll.min.js
//

document.addEventListener("DOMContentLoaded", function() {
    var e = function() {
            if ("scrollingElement" in document) return document.scrollingElement;
            var a = document.documentElement,
                b = a.scrollTop;
            a.scrollTop = b + 1;
            var c = a.scrollTop;
            a.scrollTop = b;
            return c > b ? a : document.body
        }(),
        g = function(a) {
            var b = e.scrollTop;
            if (2 > a.length) a = -b;
            else if (a = document.querySelector(a)) {
                a = a.getBoundingClientRect().top;
                var c = e.scrollHeight - window.innerHeight;
                a = b + a < c ? a : c - b
            } else a = void 0;
            if (a) return new Map([
                ["start", b],
                ["delta", a]
            ])
        },
        h = function(a) {
            var b =
                a.getAttribute("href"),
                c = g(b);
            if (c) {
                var d = new Map([
                        ["duration", 800]
                    ]),
                    k = performance.now();
                requestAnimationFrame(function l(a) {
                    d.set("elapsed", a - k);
                    a = d.get("duration");
                    var f = d.get("elapsed"),
                        g = c.get("start"),
                        h = c.get("delta");
                    e.scrollTop = Math.round(h * (-Math.pow(2, -10 * f / a) + 1) + g);
                    d.get("elapsed") < d.get("duration") ? requestAnimationFrame(l) : (history.pushState(null, null, b), e.scrollTop = c.get("start") + c.get("delta"))
                })
            }
        },
        f = document.querySelectorAll("a.scroll");
    (function b(c, d) {
        var e = c.item(d);
        e.addEventListener("click",
            function(b) {
                b.preventDefault();
                h(e)
            });
        if (d) return b(c, d - 1)
    })(f, f.length - 1)
});